Manufacture of pyranthrone derivatives



i; "UN TED zsTi i am n srrnrnnitnsonnnnsIDNEv TnoRNLnY, or BLAGKLEY, MANCHESTER, ENG- DYE'STUFFS 'conrosn'rion LIMITED, OF MAN- CHESTER, ENGLAND I Patented Dec. 16,1930

LAND, ASSIGNORS -'.ro BRITISH- TES PATENT] OFFlCE v MANUFACTURE. on EYRANTHRONE DERIVATIVES No Drawing. Application filedseptember 29,1927, SerialNo. 222,932, and in Great Britain October 3, 1926.

In a copending application Ser'. No. 217 ,540, filed, by, one. of us, Sidney Thornley on May 21, 1927, which matured into Patent No. 1,662,872 on March 20, 1928, there is disclosed the manufacture of new vat dyestufls from fiavan-throne. That application relates to a process which comprisesreactingupon fiavanthronewith hydroxyl amine or salts thereof, to form an am no derivative of fiavanthrone, and then subsequently aoylating' the amino derivative thus formed by reacting the samewith an acylating agent to produce an ac'yl-amino-fiavanthrone. These acyl-amino-flavanthrones dye cotton in brown shades in an advantageous manner. 'Wehave now foundthatfother new and z useful vat dyestuffs ofa different type may be made by' a somewhat similar procedure.

Our present invention relates to the productionoifnew vat dyestuffs from pyranthrone compounds of the class comprising pyranthrone and halogenated 'pyranthrone; 7 and it comprises .a process wherein, such pyranr throne compounds are reacted upon with hydroxylamine to form amino derivatives of the same, the said. amino derivatives being subsequently reacted with anacylating agent to convert theln into corresponding-acylamino compounds and it further comprises as new dyestuffs the amino and acyl amino compounds thus produced.

' Thepresent application is mainly directed to the amino pyranthrones and the process of 'making'the same, Ourxcopending' divisional application Ser. No. 361,844: is mainlydirectp Inmaking the amino derivat ves, we have foundjthat.the%reaction between the pyran- 4o throne "compoundand the. hydroxyl amine 7 may j beadvantageously carried out in: the; pres'ence of sulphuric acid. .Also the presence of ferrous sulphate during such react on is advantageous I By our process, pyranthroneis easily con= been introduced into the compoundra red dish brown shade is obtained on cotton. 1

ehave indicated the broad scope of our invention. Our process is capable of varlous modifications. -The time, temperature and,

such details maybevaried within certain limits. The following examples are typical embodiments of our invention andillustrate it Without limiting the scope thereof. In these examples the parts are by Weight.

Eaiam-pZe 1.- 20 parts of pyranthrone are dissolved in 400 partsof sulphuric acid, 766

Be, bystirringat 60 C, The solution is cooled, 2 parts of ferrous sulphate crystalsadded, followed, after again cooling, by the gradual addition of 10 parts of hydroxylamine hydrochloride. The temperature is raised to 165 C. and maintained at 160-165 (l, with stirring, for 2 hours.v The reaction mixture is cooled, poured into 3,000 partsof water andthe whole stirred; After separation by filtration, thev residueis washed with water until free from' acid, and dried. The substance dyes cotton" from 'hydrosulphite vat in deep brown shades. Treatment of the dyed fibre with cold sodium hypochlorite solution 4f Tw.) causes a: considerable change in the shade."

The product'of Example 1 is probably an amidated pyranthrone containing up to three I amino groups and represented by the probwhereinw is an integer probably less than 4.:

A similar product is obtained when the reaction is carried out in the absence oiferrous I ableformula I sulphate; As stated, these products are: useful intermediates and may be acylated. "In

t I ben'zoylatingthe procedure ofthefollQWing I I example may be used.

' Example .2.-1O parts 'of the driedj product I of Example 1,150 parts of nitrobenzene, and 36 parts of benzoyl chloride are heated with stirring at 170 (Tim-1%w hours. After- 3 wards, the temperature is raised to 210? C. and maintained at-205-210 O. for 2ihou'rs.

' Thereaction mixture is cooled, 280 parts methylated spirits added, stirredfor an hour, and filtered. The residue is washed with denatured alcohol'of the type'of methylated spiritsuntil free from nitrobenzene and is then' boiled with 200 parts ofwate ricontain ing parts of sodium hypochlorite (15 per cent available chlorine), for 80 minutes. This treatmentis followed by'the addition of 10 product is a dark brown substance, slightly soluble .in hot 'nitrobenzen'e or aniline giving orange brown solutions,- insoluble in water, soluble in concentrated sulphuric acid to a blue solution which r'eddenswhen'heated with a little boric acid. The' product is hydrolyzed by the heating with 8Qperjcent sulphuric 'acid giving an aminated pyranthrone and benzoic acid The compound gives a reddish violet Vat with alkaline hydro'sulphite, frorn'which cottonis dyed reddish brown; The shade is i ast to chlorine. The formula of thebenzoylated'derir c I I v. comprises condens ng a pyranthrone comative is probably I wherein m an integer probably lessthan 4.

In place of thebenzoyl chloride in this example, we may use other acylating agents 7 such as acetic anhydride, acetyl chloride, ox-

alyl chloride, anisoyl chloride, etc. Bythis means Various shadesofbrown may be obtained. Q

The vat dyestuffs produced by this a cylating process are dark coloured substances, in- I soluble in water but slightly soluble in organic solvents. They are hydrolyzed by heating With per cent sulphuric 'acid, giving amidated pyranthrones and carboxylic'acid, *RCOOH. These acyl'atedvat dyestuffs may. berepresented by the probable formula wherein m is anrinteger fprobably less than 4 and COR represents an acyl radical.- I

lvhat we claim and desire to secure by Letters Patent is I ,I v P 1. In the manufacture of Vat dyestufis use ful also as intermediates inthep roductionof f other dyes'by acylating, the process which comprises condensingfa -pyranthrone com pound'of the class consisting of'pyranthro'ne and halogenated pyranthrone, with hydroxyl amine. I I 7 2. In the manufactureof vatjdyestufis use. ful also as intermediates in the production of other dyes by acylating, the process which comprises condenslng a pyranthrone compound ofthe class consisting of pyranthronel I and halogenated pyra-nthrone, withhydroxyl amine in the presence of sulphuric acid. 7 I 3. In the manufacture of vat dyestuffs use; ful also as interInediates in the production of other dyes by a'cylating,the processwhich pound of the class consisting of pyranthrone and halogenated pyranthrone, with hydroxyl 4. As anew composition of matter useful v in d e br ws-s ades c an in a e amine in the presenceof-sulphuric; acid and; 4 l ferrous sulphate. V

" for dyeing du ction 0 V substance produced by the reaction of a pybyr cold sodium hypochlorite solut-ion, said substancehaving the probable formula II O V wherein an is an integer probably less than 4.

15. As anew composition of matter useful and as an intermediate in the proacylated dyestuffs, a dark coloured ranthrone compound of the class consisting of pyranthrone and halogenated pyranthrones With hydroxyl amine, said substance dyeing cotton from a hydrosulphite Vat in deep Y brown shades changed in shade by cold sodium v hypochlorite solution, said substance being obtainable by the process of claim 2 and capable of being converted by acylation into acylated dyestuffs which are also dark coloured substances and which are insoluble in tures;

Water but slightly solublein organic solvents.

' In testimony whereof we aflix our signa- 

